Prior to the present invention, 2,4-dihydroxybenzophenones such as Eastman 2,4-DHPB, manufactured by the Eastman Kodak Company, Rochester, N.Y., were used extensively as ultraviolet screens for the protection of various thermoplastics, such as polycarbonates, polyesters, etc. In determining whether a particular UV stabilizer is effective, the stabilizer can be incorporated into an organic resin, for example, melamine at about a 3% by weight of the total coating composition and thereafter applied onto the surface of the thermoplastic substrate, for example, a sheet and cured. Those skilled in the art, however, are constantly evaluating various UV stabilizers in order to optimize the protection afforded by such stabilizers to the thermoplastic substrates which are treated with such materials.